I think it's absolutely critical that the partner who had an EA be able to identify it as such. My H spent months insisting he and his EA were "just friends" and all other possible minimizations--but as long as he was in denial, he couldn't address why it happened, how to get past it, and any emotional impact it had had on me.
He managed for some time to polarize his thoughts: PAs were despicable, whereas EAs could not be considered affairs (and by extension, could not impact the marriage in the same way). For him to recognize that he'd actually had an affair was a huge step towards being able to rebuild. I feel that until the emotional component has been admitted to, it's not possible for the partner having the EA to turn his/her emotions back towards the spouse.
